Method for fault detect, report, and maintenance negotiation control of multi-segment pseudo wire

Abstract

A method for fault detect, report and maintenance negotiation control of the multi-segment pseudo wire. The method of detect is that an end-to-end detection message which is transmitted by a source node is transparently transmitted by a switching node to an ultimate node, thereby realizing the end-to-end detection. The method for reporting the fault is that the switching node transmits a fault notification message transparently transmitted and carrying the fault information to a downstream ultimate node when detecting the fault. The method of maintenance negotiation control is that the fault detection information and the fault reporting capability information are carried in the established message during establishing the multi-segment pseudo wire and enables the terminal to flexibly select the maintenance method which accords with the predetermined policy according to the finally supported capability.

1 . A method of end-to-end fault detection for a multi-segment pseudo wire, comprising: 
 sending an end-to-end fault detection message by a first Ultimate Provider Equipment (U-PE) of a Multi-Segment Pseudo Wire (MS-PW) in accordance with a predetermined triggering condition or by a predetermined time;    receiving and transparently transmitting the end-to-end fault detection message hop by hop downstream by Switching PEs (S-PEs);    determining the MS-PW as failed by a second U-PE, if the end-to-end fault detection message in accordance with the predetermined triggering condition or by the predetermined time is not received.    
   
   
       2 . The method according to  claim 1 , wherein the end-to-end fault detection message contains a first identification information, which is used to identify whether a received message is an end-to-end fault detection message.  
   
   
       3 . A method of end-to-end fault detection for a multi-segment pseudo wire, comprising: 
 sending an end-to-end fault detection message by a first Ultimate Provider Equipment (U-PE) of a Multi-Segment Pseudo Wire (MS-PW);    receiving and transparently transmitting, by Switching PEs (S-PEs), the end-to-end fault detection message hop by hop to a second U-PE downstream;    upon receiving the end-to-end fault detection message, returning a response message to the first U-PE by the second U-PE; and    if the response message is not received before a response time of the end-to-end fault detection message expires, determining the MS-PW as failed.    
   
   
       4 . The method according to  claim 3 , wherein the end-to-end fault detection message contains a first identification information, which is used to identify whether a received message is an end-to-end fault detection message.  
   
   
       5 . A method of fault report for a multi-segment pseudo wire, comprising: 
 if a Single-Segment Pseudo Wire (SS-PW) of a Multi-Segment Pseudo Wire (MS-PW) is determined by a Switching Provider Equipment (S-PE) involved in the SS-PW as failed, creating and sending a fault notification message carrying fault information downstream by the S-PE;    forwarding, by downstream S-PEs, the fault notification message to an ultimate Provider Equipment (U-PE) hop by hop transparently, or receiving the fault notification message by an ultimate Provider Equipment (U-PE) at downstream;    obtaining the fault information from the fault notification message by the U-PE.    
   
   
       6 . The method according to  claim 5 , wherein an SS-PW is determined by the S-PE as failed in the following way: 
 sending, by a Provider Equipment (PE) connected to one end of the SS-PW, a single-segment fault detection message to an opposite end in accordance with a predetermined triggering condition or by a predetermined time; if the single-segment fault detection message is not received in accordance with the predetermined triggering condition or by the predetermined time, determining the SS-PW as failed; or    sending, by a Provider Equipment (PE) connected to one end of the SS-PW, a single-segment fault detection message to an opposite end; and if a response message to the single-segment fault detection message from the opposite end is not received within a preset time, determining the SS-PW as failed.    
   
   
       7 . The method according to  claim 5 , further comprising: upon detecting a Tunnel fault, or a PW state notification fault, or a local PE fault, creating a fault notification message carrying fault information and sending the fault notification message downstream by the S-PE.  
   
   
       8 . The method according to  claim 6 , wherein the fault notification message contains a second identification information, which is used to identify whether a received message is a fault notification message; and/or 
 the single-segment fault detection message contains a third identification information, which is used to identify whether a received message is a single-segment fault detection message.    
   
   
       9 . The method according to  claim 8 , wherein the fault information comprises fault type information and fault location information.  
   
   
       10 . A method of maintenance negotiation control for multi-segment pseudo wire, comprising: 
 B1. creating a positive setup message for a Multi-Segment Pseudo Wire (MS-PW) by a source Ultimate Provider Equipment (U-PE); the positive setup message containing information on fault information report capability and fault detection capability supported by the source U-PE;    B2. receiving, by Switching Provider Equipments (S-PEs), the positive setup message hop by hop, and determining whether the fault information report capability is supported locally and whether the fault detection capabilities are partially supported locally; if all or part of the fault information report capability and the fault detection capabilities is supported, keeping only information on the locally supported capabilities in the positive setup message, forwarding the positive setup message, and going to step B3; if none of the fault information report capability and the fault detection capabilities is supported, going to step B4;    B3. upon receiving the positive setup message, determining by the terminal U-PE whether the kept capabilities are supported locally; if all or part of the kept capabilities is supported, determining to perform an MS-PW maintenance operation in a supported capability information set in accordance with a local policy; if none of the kept capabilities is supported, otherwise going to step B4;    B4. disconnecting an established PW segment.    
   
   
       11 . The method according to  claim 10 , between the steps B3 and B4, further comprising: 
 B31. sending a reverse setup message for the MS-PW to the source U-PE by the terminal U-PE; the reverse setup message carrying information on fault information report capability and fault detection capability supported by the terminal U-PE or carrying the supported capability information set;    B32. receiving by the S-PEs the reverse setup message hop by hop, and determining whether the fault information report capability is supported locally and whether the fault detection capabilities are partially supported locally; if all or part of the fault information report capability and the fault detection capabilities is supported, keeping only information on the locally supported capabilities in the reverse setup message, forwarding the reverse setup message, and going to step B33; if none of the fault information report capability and the fault detection capabilities is supported, going to step B4;    B33. upon receiving the reverse setup message, determining by the terminal U-PE whether the kept capabilities are supported locally; if all or part of the kept capabilities is supported, determining to perform an MS-PW maintenance operation in the supported capability information set in accordance with a local policy; if none of the kept capabilities is supported, otherwise going to step B4.    
   
   
       12 . The method according to  claim 11 , wherein 
 the fault information report capability refers to: if a Single-Segment Pseudo Wire (SS-PW) fails, a U-PE or S-PE involved in the SS-PW can create and send a fault notification message carrying fault information to a downstream S-PE or U-PE, and can identify and process the fault notification message;    the fault detection capability refers to: the U-PEs or S-PEs can identify and process end-to-end fault detection messages for the MS-PW and/or single-segment fault detection messages sent between Provider Equipments (PEs).    
   
   
       13 . The method according to  claim 12 , wherein if all U-PEs and S-PEs support the fault information report capability and can identify and process the end-to-end fault detection messages, the MS-PW is maintained as follows: 
 if a Single-Segment Pseudo Wire (SS-PW) of the MS-PW is determined by a Switching Provider Equipment (S-PE) involved in the SS-PW as failed, creating and sending a fault notification message carrying fault information downstream by the S-PE;    forwarding, by downstream S-PEs, the fault notification message to a U-PE hop by hop transparently, or receiving the fault notification message by a U-PE at downstream;    obtaining the fault information from the fault notification message and performing maintenance on the MS-PW in accordance with the fault information by the U-PE.    
   
   
       14 . The method according to  claim 13 , wherein an SS-PW is determined by the S-PE involved in the SS-PW as failed in the following way: 
 sending, by a PE connected to one end of the SS-PW, a single-segment fault detection message to an opposite end in accordance with a predetermined triggering condition or by a predetermined time; if the single-segment fault detection message is not received in accordance with the predetermined triggering condition or by the predetermined time, determining the SS-PW as failed; or    sending, by a PE connected to one end of the SS-PW, a single-segment fault detection message to an opposite end; and if a response message to the single-segment fault detection message from the opposite end is not received within a preset time, determining the SS-PW as failed.    
   
   
       15 . The method according to  claim 14 , further comprising: upon detecting a Tunnel fault, or a PW state notification fault, or a local PE fault, creating a fault notification message carrying fault information and sending the fault notification message downstream by the S-PE.  
   
   
       16 . The method according to  claim 11 , wherein if all U-PEs and S-PEs support only end-to-end fault detection messages, the MS-PW is maintained as follows: 
 sending, by a first Ultimate Provider Equipment (U-PE) of the MS-PW, an end-to-end fault detection message in accordance with a predetermined triggering condition or by a predetermined time;    receiving and transparently transmitting the end-to-end fault detection message hop by hop downstream by the S-PEs;    determining the MS-PW as failed by a second U-PE, if the end-to-end fault detection message is not received in accordance with the predetermined triggering condition or by the predetermined time.    
   
   
       17 . The method according to  claim 11 , wherein if all U-PEs and S-PEs support only end-to-end fault detection messages, the MS-PW is maintained as follows: 
 sending an end-to-end fault detection message by a first Ultimate Provider Equipment (U-PE) of the MS-PW;    receiving and transparently transmitting, by S-PEs, the end-to-end fault detection message hop by hop to a second U-PE downstream;    upon receiving the end-to-end fault detection message, returning a response message to the first U-PE by the second U-PE; and    if the response message is not received before a response time of the end-to-end fault detection message expires, determining the MS-PW as failed.    
   
   
       18 . The method according to  claim 13 , wherein the positive setup message and/or the reverse setup message further contains information on supported fault detection capability, and the U-PEs or S-PEs choose supported fault detection messages for detection in accordance with an ultimate intersection of capability information.  
   
   
       19 . The method according to  claim 12 , wherein 
 the end-to-end fault detection message contains a first identification information, which is used to identify whether a received message is an end-to-end fault detection message; and/or    the fault notification message contains a second identification information, which is used to identify whether a received message is a fault notification message; and/or    the single-segment fault detection message contains a third identification information, which is used to identify whether a received message is a single-segment fault detection message.    
   
   
       20 . The method according to  claim 13 , wherein the fault information comprises fault type information and fault location information.  
   
   
       21 . The method according to  claim 7 , wherein the fault notification message contains a second identification information, which is used to identify whether a received message is a fault notification message; and/or 
 the single-segment fault detection message contains a third identification information, which is used to identify whether a received message is a single-segment fault detection message.    
   
   
       22 . The method according to  claim 16 , wherein the positive setup message and/or the reverse setup message further contains information on supported fault detection message type capability, and the U-PEs or S-PEs choose supported fault detection messages for detection in accordance with an ultimate intersection of capability information.  
   
   
       23 . The method according to  claim 17 , wherein the positive setup message and/or the reverse setup message further contains information on supported fault detection message type capability, and the U-PEs or S-PEs choose supported fault detection messages for detection in accordance with an ultimate intersection of capability information.  
   
   
       24 . A Fault Information Notification (FIN) message in a Multi-Segment Pseudo Wire (MS-PW), comprising: 
 a header, containing a second identification information, adapted to identify whether the message is a fault information notification message; and    a payload, containing: FIN message type indication, adapted to identify that the message is adapted for fault information report; fault location information, adapted to identify fault location; and fault type information, adapted to identify fault type.    
   
   
       25 . The Fault Information Notification message according to  claim 24 , wherein the header further comprises: Transport tunnel label and Pseudo Wire label.